Charles Darwin

/ An English naturalist who, along with Alfred Russell Wallace, developed the theory of evolution through natural selection. It is Darwin’s name that is most closely associated with the theory of evolution.
Species / A group of closely related organisms that are capable of mating and producing fertile offspring.
Mutation / A change in the genetic material (DNA) of an organism.
Adaptation / Any characteristic or trait of an organism that improves its chances of surviving in its environment.
Natural Selection / The means by which evolution takes place. Organisms that are best adapted survive. Nature “selects” organisms with helpful traits. Those with harmful traits do not usually survive to reproduce.
Overpopulation / The production of more offspring than can possibly survive.

Variation

/ Differences among individuals in a species.
Competition / The interaction between organisms striving for the same goals: food, water, space, mates, etc.
Selection / Organisms that are best adapted survive. Nature selects organisms with helpful traits that make them well adapted for a particular environment.
Geographic Isolation / The geographical separation of one population of a species from another.
Fossil / The preserved remains or traces of an organism that lived in the past.
Sedimentary Rock / Rock formed by the laying down of sediments – particles of sand and rock carried most often by water.
Dating Methods / Ways to estimate the age of fossils
Relative Dating / Reading the layers of sediment to determine the oldest and youngest fossils. The oldest fossils are usually in the bottom layer; the youngest in the upper layers.
Absolute Dating / Determining the amount of radioactive elements that are present in a fossil. The amount that is left in the rock tells scientists how old the fossil is.
Extinct Organisms / Organisms that no longer live on Earth.
Fossil Record / The millions of fossils that scientists have collected.
Geologic Time Scale / A chart of calendar that shows when the major groups of organisms lived over the Earth’s 4.6 billion year history.
Evolution / A change in a species over time through natural selection.
Gradualism / Evolution that takes place gradually over time.
Punctuated Equilibrium / Evolution that takes place rapidly especially as a result of a catastrophic environmental event.
Ways to show evolutionary relationships / Body structure
Development before birth (embryology)
DNA sequences
Homologous Structures / Structures that are similar in form but different in use such as the flipper of a whale and the wing of a bird.
Branching Tree / A diagram that shows how different groups of organisms are related.